Vehicle brake



Nov. 13,1928. 1,691,083

- J. s. REYNOLDS f VEHI CLE BRAKE.

Filed Oct. 10, 1925 2 Sheets-Sheet 1 K 2 y; INVENTOR.

Joy 5. EfX/VOLZZS Z Z By M ATTORNEY.

Nov. 13, 1928. 1,691,083

J. s. REYNOLDS I VEHI CLE BRAKE Filed Oct. 10, 1925 2 Sheets-Sheet 2INVENTOR. (Zr .5, E'Y/VOLOE A TTORNEY.

Patented Nov. 13, 1928.

UNITED STATES JO! 8. REYNOLDS, 6F DETROIT, MICHIGAN.

- VEHICLE BRAKE.

.Applicatlon filed October 10, 1925. Serial No. 61,653

This invention relates to vehicle brakes, and the purpose and object ofthe invention is to provide a simple and efiicient brake mechanism ofmechanically operated type involving a means for application of pressureat two points of the band in the direction of rotation of the drum withwhich the band is associated.

The novel features of the invention reside in the relationship Off theparts by means of which the band is caused to engage the druni, thearrangement of the band to rotate or to turn with the drum to a limitedextent and means utilizing the torque developed at two points on theband.

In the usual brake band, either of the internal expanding type or theexternal contracting type, practically one-half of the band is moved toengagement with the drum in the direction of rotation of the drum andthe other half is moved in a direction 0 posite to the direction ofrotation of the rum and therefore such construction lack in eflic1ency.'In the construction of brake band in accordance with my invention bothhalves of the band are brought to engagement with the drum in thedirection of rotation of the drum. There- "fore, what is known as thewrapping action is utilized thereby resulting in a higher eiiiciency perpound of pressure utilized in setting the brake. These and other objectsand various novel features of the invention are more fully described andclaimed, and a-brake construction embodying my invention is shown in theaccompanying drawings in whioh- I Fig. 1 is an elevation of a brake bandof the internal expansion type embodying my invention.

Fig. 2 is a section taken on line 2-2 of Fig. 1. 1

Fi 3 is an elevation similar to Fig. 1 showing the position of the partsupon application of ressure to set the brake.

ig. 4 is a section taken on line 4-4 of Fig. 1 showing the connection ofthe torque arm to the band.

Fig. 5 is a detail of the rocker block used at the point of connectionof the torque arm to the hand as hereinafter described.

I have here elected to show the internal expanding type of band, suchtype being most adaptable to utilization of my invention, but it is tobe understood that the princi 1e here involved ma be utilized with ban 5other than the sp it internalv expandingtype as previous types of brakehand with the axis of the drum is one-half the socket 16.

shown without departing from the spirit and scope of this invention.

Referring more partioularl to Fig. 2, the usual brake drum 1 is attachedto the wheel of a vehicle, a portion of Fig. 1. The drum has the usualperipheral flange 2 and the brake band 3 is housed within this flangebein covered by a cap plate 4 provided on one si e of the drum fittingwithin the flange and secured to a stationary part 5 of the axlehousing. Rotatably mounted upon this housing within the drum is thetorque lever or arm 6, one end 7 of which is provided at the end withthe flattened portion 8 lying within a cylindrical recess or socket!)provided on the band at a point diametrically opposite the. split(portion thereof, the two an s being indicate at 10 and 11. This part 8is rectangular in form having opposite arallel side faces and the rockblocks 12 an 13 are fitted between the flat faces and respective sidesof the socket 9, the axis of which is parallel to the axis of the drumor wheel. As

indicated in Fig. 4 the portion of the hand in which this cylindricalaperture 9 is formed is slotted at 14' on opposite sides of the wallforming the recess and on the inner periphery to permit the portion ofthe arm 7 connecting art 8 to occupy a position as indicated in ig. 3.The socket 9 is open on that side facing the center of the band whichpermits the block 8 torock therein as is required in the movement of thearm from the position shown in Fig. 1 to that shown in Fig. 2. In itspreferred form the 0 arm 6 is formed to provi e a cylindrical socket 16open on one side and similar in all general respects to the socket 9 andthe length of the armlfi from the center of the recess 16 to the lengthof the which is indicated in r posite end 15 of the arm 7 from the axisof the recess 9 to the axis of: the drum. There is also a lever 17 whichis supported on a stationary pivot 18 carried by the stationary plate 4as shown in Fig. 2. This lever 17 has an end portion 19 formed withparallel sides extending into the recess 16 of the torque lever 6 asshown in Fig.1 and there are rock blocks 20 similar to the blocks 12provided on each side face of the portion 19 fitting this cylindricalaperture or The socket 16 is open at one side to permit introduction ofthe ortion 19.

v s shown more particular y in Fig. 2 this lever 17 is formed of twoparts indicated at 17, and l'i' which are practically identical in formand together provide a lever having a with the brake operating in form.

bifurcated end. Between the legs of this bifurcated end is a cam 21supported on or formed integrally with the shaft 22 which extendsthrough an elongated opening 23 in the stationary plate 4 and througheyes in said bifurcated ends. To the projectihg end of this shaft issecured the lever 24 connected rod 25 as shown in Fig. 1. It is to benoted from Fig. 1 that this cam 21 extends to one side only of the shaft22 and that on the opposite side the portion 26 of the cam part is trulycircular This cam member 21 lies between the adjacent ends 10 and 11 ofthe brake band which has end portions shaped to engage the cam as willbe understood from Fig. 1.

It is also to be understood that, upon the lever 24 and the brake. rod25 being moved to the right from the position shown in Fig. 1 to theposition. indicated. by full lines in Fig. 4, the said cam portion willbe moved against the end 10 of the said brake band tending to force itinto engagement with the drum 1 which it is to be understood is rotatingin the direction of the arrow shown in Fig. 3. Due to the elongated slot28 there is possibility of movement of the cam shaft 22 to the positionshown in Fig. 3 the lever 17 being turned on its pivot and therebyturning the lever 6 on its pivot. Due to this cam 21 bein only one sideof the shaft, the turning of the cam shaft 22 by the brake rod andlever, the part 10 of the brake band is moved to engagement with thedrum in the direction of rotation of the drum. lllhis movement tends toturn the band around with the drum with which it is free to turn to theextent permitted by the levers 6 and 17. The movement of the band withthe drum causes the end 11 to exert ressure on the cam shaft tending tomove it from the position shown in Fig. 3 and tending to move the end 7of the torque arm '3 in the direction of the arrow.

shown thereon in Fig. 3. The actual position of the torque levers 6 andupon the turnin of the cam 21 to the position shown in Fig.3 will bebetween the extreme positions shown in Figs. 1 and 3 respectively andwith the split ends 10 and 11 approximately equidistantly positioned onopposite sides of the diametrical line passing through the axis of thedrum and axis of the pivot pin 18 and thus finally the cam shaft 22provides a limit for movement of the end 11 with the drum and the effectof pressure in setting the lower half of the band will be through and bymeans of the end of the torque lever 6. The torque is thus applied attwo points of the band at the point or end 10 of the band which insetting the brake causes the band to turn with the drum which insequence causes the lever end 7 toturn and as the shaft 22 provides astop for the end 11 of the brake band, that half of the band has thepressure actually applied through the lever arm 7 in the comparativelyinexpensive,

.ment is secured. It is also evident that 1? immediately the directionof rotation of the drum in the same manner as that half of the bandhaving the end 10. Thus, the application of the torque or brake pressureat two points being in the direction of rotation of the drum advantageis taken of the Wrapping action resulting from the setting of the bandon each half of the band equally. In former constructions utilizing thetwo point cam for spreading the free ends of an expanding type of brakeband, one-half of the band is caused to be moved to its seat in thedirection. of rotation and other half in the direction opposite theretoso that the last mentioned part of the band is not as effective in itsengagement with the drum as the first half. It is to obviate thisinequality of pressure in the application. of the brake that is disensed with by the construction herein descri ed.

Preferably the lever 17 from the center of the pivot point to the centerof the socket 16 is one half the length of the lever from the center ofthe pivot pin to the center of the cam shaft. Thus, pressure of the bandtending to turn the arm 17 on its pivot is applied at twice the pressureon the center of the re cess 16 and this again is divided due to therelationship of the arm 15 and 7 so that at the point 8 the samepressure is applied as is ap )lied at the point 22.

referably, and as is the usual practice, the face of the band is linedwith a bralze lining as indicated at 26 providing a proper character ofsurface for engagement with the inner face of the flange of the brakedrum. The application of pressure at two points of the band by theconstruction described is automatic in character and the brake is ofmechanically operated, type as distinguished from hydraw lic types inuse and by the arrangement described a greater eiiiciency in the brakingell:-

t e device is simple and inexpensive in construction and is also of acharacter of minimum liability to get out of order. Havin thus fullydescribed my invention, what I c aim and desire to secure by LettersPatent of the United States is-- 1. In a vehicle brake, the combinationwith a rotatable brake drum and stationary axle housing, of a platemounted on the housing, a split internal expanding brake band within thedrum, a lever within the drum pivoted on the said housing, a hingeconnection between an end of the lever and the band at a pointpractically opposite the split point, a second lover, a stationary pivottherefor carried by the late, a'cam having a single point positionebetween the two ends of the band, a shaft for the cam, the second leverhaving. one, end pivotally connected with the shaft a slot in the platethrough which the shaft extends permitting movement of the shaft, thesaid second lever having its opthe pressure posite end in hingedconnection with warm of the first lever, thearms of said levers beingsubstantially in such relationship that applied by the cam to expand theband is also equally applied at the point of the hinged connection ofthe first named lever with the-band," the said levers limiting theextent of rotative movement of the band with the drum.

2. In a vehicle brake, the combination with a brake drum, of a splitinternal expanding brake band having a socket at a point diametricallyopposite the split point, a lever pivoted on the axis of the drum andhaving an arm terminating in the said socket and an arm at theop'ppsiteside of the axis also provided with a socket, a stationarilypivoted lever having an end portion extending into the socket of thefirst named lever, and an arm extending to between the band ends, ashaftcarried by the said arm, a cam on the said shaft engaged by the two endsof the band, and means for turning the shaft and cam to spread the bandto engagement with the drum,

said band being adapted to turn with the' drum.

3. In a vehicle brake, the combination with a brake drum, a stationaryaxle housing relative to which the drum is rotatable and a stationaryplate, of a split internal expanding brake band within the drum,manually operable means for spreadin the band at the split pointincluding a cam Imving'a single high pointwhereby pressureis exerted onone'ofthe said band ends to expand the band, a lever carrying the saidcam, a pivot therefor mounted on the said stationary plate, a rock leverpivoted on the stationary axle housing and having an end engaged by theend of the said first named lever on the opposite of the pivot pointfrom the said cam, the opposite end of the said lever engaging the bandpractically diametrically opposite the s lit portion of the band, saidband being a apted to turn with the drum to an extent permitted by thesaid levers.

4. In a vehicle brake, the combination with a brake drum, of a brakeband adapted to be brought to frictional engagement with the drum, theband being mounted to turn with the drum,'the said means including alever pivoted to turn on the axis of the drum, and a second leverstationarily pivoted, the said second lever carrying and supporting theposite end having a hinged connection with the band and the two leverstogether limiting the extent of movement of the band with the drum andproviding a means whereby the pressure in settin the band and the torquedeveloped there y is applied at two points on the band.

5. In a vehicle brake, the combination with a brake drum, of a brakeband adapted to be brought to frictional engagement therewith, mechanismfor causing said'engagement,

of the band with the drum comprising two levers mounted on stationarypivots, one of said levers having an arm in hinged relationship with theband at one end and in hinged relationship said other lever carrying atits opposite end means for causing engagement of the band with the drum,said levers limiting the exwith the other lever at the other,

tent of movement of the band with the drum.

6. In a vehicle brake, the combination with a brake drum, of a splitexpansible band for engaging the drum an expanding element between thetwo ends of the band and leverage means actuated through actuation ofthe expanding element to apply pressure tothe band at a pointapproximately diametrically opposite the split point whereby each halfpart of the band is caused to engage the drumpractically simultaneouslyin the direction of its rotation, said leverage means limiting theextent of movement of the band with the drum.

7. In a vehicle brake, the combination with a brake drum, of a splitexpansible band for engaging a drum, an expanding element between thetwo ends of the band, anda pivoted lever connected with the band at apoint approximately point and actuatable through actuation of theexpander, the said expander and the said lever causing application ofpressure to the band at two points and in the direction of rotationof'the band and further limiting the Extent of movement of the band withthe rum.

tion.

JOY s. REYNOLDS.

diametrically opposite the split

